Lameness represents one of the greatest threats to the health and racing careers of racehorses and is particularly relevant with Standardbreds that are used in harness racing. Harness racing involves connecting a sulky, or bike, to the racehorse, which is driven by a rider sitting rearwardly of the sulky. The sulky typically includes a frame, two wheels, a seat for the rider and two elongate shafts for connecting to a horse harness on either side of the horse. The rider sits on the seat and controls the horse using reins. In harness racing, a generally oval racetrack is used, which is banked upwards and away from the center. During a race, the workload performed by the horse includes transport of its own mass against air resistance, the track surface, centrifugal forces as well as the sulky and rider's mass. The rider's center of mass is typically located behind the wheel axles, which causes the sulky to lift upwardly at the sulky shafts and hinder the horse's natural running gait. Moreover, the horse's natural running gait causes the horse's sides lateral torso to move up and down during full forward and rearward limb extensions, with the force of this action being transferred to the sulky wheels via the harness connector and the sulky frame thereby causing the sulky wheels to oscillate. The aforesaid factors combine to decrease the efficiency of the horse's running form, which in turn can significantly reduce the speed and comfort of the horse. Moreover, current sulky designs and the track's banking combine to cause upper body and lower leg injuries to the horse. This may significantly reduce the racing career of the horse and cause costly veterinarian bills.
Many designs of sulky shaft connector exist, a few examples of which are as follows:                U.S. Pat. No. 4,326,367, issued Apr. 27, 1982 to Cashman for “Racing Sulky and Harness”;        U.S. patent application No. US2003/0009997, published Jan. 16, 2003 to Knox for “Apparatus and Method for Quickly Releasing a Harness from a Vehicle”;        U.S. Pat. No. 6,446,419, issued Sep. 10, 2002 to Terwilliger for “Swivel Joint Quick Hitch for Harness Racing”; and        U.S. Pat. No. 4,480,428, issued Nov. 6, 1984 to Gilbertson for “Shaft Coupler”; and        U.S. Pat. No. 4,473,991, issued Oct. 2, 1984 to La Mura for “Harness Connector”.        
The aforesaid designs suffer from a number of important drawbacks. Disadvantageously, none of the designs appears to be of sufficient flexibility in the harness system to allow the horse's movements to be independent of the sulky shafts. Some of the designs are of a complex construction, which may add mass to the harness. One design appears to allow only a restricted swiveling movement of the harness relative to the sulky shaft. In addition, some designs appear to be only suitable for statically connecting the sulky shafts to the harness and may be unsuitably inflexible to allow independent cushioning of the sulky shafts during normal racing conditions. Furthermore, the designs all appear to rely on an interference fit between the sulky shaft end and the harness connector, which may not be suitable to enable independent extension and retraction of the sulky shafts during racing and banking.
Thus there is a need for an improved racing sulky shaft connector device and shaft connector member thereof.